Year	per person
1800	0.9373
1820	0.9373
1913	0.9538
1950	0.9604
1951	0.9762
1952	0.992
1953	1.009
1954	1.024
1955	1.041
1956	1.058
1957	1.075
1958	1.093
1959	1.111
1960	1.12
1961	1.104
1962	1.088
1963	1.138
1964	1.167
1965	1.159
1966	1.182
1967	1.195
1968	1.213
1969	1.181
1970	1.226
1971	1.24
1972	1.275
1973	1.216
1974	1.159
1975	1.289
1976	1.429
1977	1.505
1978	1.446
1979	1.768
1980	1.537
1981	1.462
1982	1.355
1983	1.392
1984	1.428
1985	1.435
1986	1.499
1987	1.5
1988	1.47
1989	1.59
1990	1.571
1991	1.526
1992	1.621
1993	1.549
1994	1.557
1995	1.63
1996	1.662
1997	1.733
1998	1.776
1999	1.851
2000	1.874
2001	2.051
2002	2.086
2003	2.181
2004	2.178
2005	2.252
2006	2.336
2007	2.379
2008	2.44
2009	2.492